How Many Holes Are There?

So my wife and I played Oak Grove for the first time this weekend. We tried using the course map from the website to navigate our way through. Some spots were confusing however. It seemed that there were extra holes set up throughout the course (Tee near basket for 5 with a basket between 5 & 6 tees, and tee after basket for 12 with basket towards 13 tee). Are these holes part of the course? We just kind of followed the crowd in front of us, but I'd like to know in case we go back. Are there 19 holes as the website indicates? 21? More? HELP!